Which world cities are at risk from flooding?

Many of the world's cities are low lying and threatened by flooding. Bangkok, in Thailand, and Venice, in Italy, are typical old cities built by water because they relied on shipping. Both cities are built on mud and are gradually sinking, increasing the risk of flooding.

Sea levels around the world are predicted to rise during this century, with the possibility of devastating flooding in places. Many cities in the Netherlands are below or at sea level.

They are always in danger of flooding although elaborate defenses help to protect them. The Thames Barrage has been built to prevent high tides flooding the city of London.